Not trying to extract the bad parts here – this looks like a lot of effort went into it and it certainly is useful – but there are a few wrinkles: [[ $? ]]

Not trying to extract the bad parts here – this looks like a lot of effort went into it and it certainly is useful – but there are a few wrinkles: [[ $? ]] is always true, even if $? is non-zero; it only checks if $? is non-empty. A working check for successful exit status would be (for Bash) if (($?)); then echo "not successful" else echo "succesful" fi For prompt configurations: the article hardcodes the "$" sign. A useful feature is to indicate when the user is root by switching to "#"; this can be achieved by escaping the "$". $ declare -p PS1 declare -- PS1="\$ " $ sudo bash # exit bash $ And lastly, the examples should be careful about quoting. This function mkcd { local target=$1 mkdir -p $target cd $target } breaks when called like mkcd 'has space' because $target expands unquoted. Or mkcd '*' would expand to all files in the directory. The colour section doesn't mention true colour support; many terminal emulator come with it these days, see https://gist.github.com/XVilka/8346728 https://gist.github.com/XVilka/8346728.